1. Field of the Invention
This invention relates to a device for handling lug scrap strips produced by the slitting of metallic strips in a metallic strip slitter. The apparatus handles lug scrap strips formed either by slitting a wide metallic strip into a plurality of narrow metallic strips by means of slitter knives, or by slitting the wide metallic strip lugs from both sides of the wide metallic strip. More specifically, it relates to a lug scrap strip handling device which is suited to use with a metallic strip slitter of the type used to produce thin metallic strips.
2. Description of the Prior Art
Referring to FIGS. 4 through 6, a conventional handling apparatus for lug scrap strips from a metallic strip slitter will be explained.
A wide and thin metallic strip 1 (e.g., aluminum or its alloy having a thickness of 0.4 mm or less) from a coil on a core 20 of an uncoiler 2 is continuously delivered by a pair of pinch rollers 30 in the direction indicated by arrow A in alignment with a slitter 3a. Subsequently, the metallic strip 1 is flattened while being guided by guide rollers 31 and 32 in a S-letter path. Then, the metallic strip 1 is fed by another pair of pinch rollers 33 into slitter knives 3.
The metallic strip 1 is slit by the slitter knives 3 and divided into a plurality of narrow metallic strips 10 as a product and lug scrap strips 11 at beth edges.
The metallic strips 10 as a product are passed through a pair of pinch rollers 34, a loop pit 35 and another pair of pinch rollers 36, and then rolled round a core 40 of a coiler 4.
The resulting lug scrap strips 11 are guided to an air duct 5a in a lug scrap strip treatment device b by other pinch rollers b1 and b2, and then cut and crushed by a blower/crusher 5.
As shown in FIGS. 5 and 6, the blower/crusher 5 comprises: a rotating blade 50 mounted on the end of a rotating shaft 51; a casing 52 for accommodating the rotating blade 50 and rotatably supporting the rotating shaft 51; an admission port 53 formed in the casing 52 facing the rotating blade 50; and an exhaust port 54 formed in the casing 52 so as to extend in the direction of rotation of the rotating blade 50.
Since rotary cutting blades 55 for crushing and fixed cutting blades 56 are attached to the rotating blade 50 and the admission port 53 of the casing 52, respectively, a long lug scrap strip 11 entering through the admission port 53 is cut, crushed and deformed by these cutting blades 55 and 56. The resulting cut and crushed pieces 12 are passed through the air duct 5b, shown in FIG. 4, are fed to a cyclone type scrap collector 6 and are then released into a chamber 70 of a scrap press 7 provided under discharge port 60 in the lower portion of the scrap collector 6.
When the crushed pieces 12 within the chamber 70 reach a predetermined quantity or more, the crushed pieces 12 are pressed by a piston 71, moving to the right in the drawing, to be compacted into a mass, and thereafter removed by opening a gate 72.
In the lug scrap strip treatment device b of the prior art described above, the long lug scrap strip 11 is cut and crushed by the blower/crusher 5 and the cut and crushed pieces 12 vary extremely in length. Hence, there is a problem in that the crushed pieces 12 cut in longer sizes than the minimum inner diameter of the air duct 5b at the rear of the blower 5 are easily caught on the internal surfaces of the air duct 5b and the exhaust port 60 of the scrap collector 6, and a majority of problems encountered are caused by the plugging-up of the scrap strip pieces in the air duct 5b and the scrap collector 6.
The problems due to the plugging-up by the scrap strip pieces happen more often when the metallic strip 1 is thick than when it is thin.